1. Technical Field
The present invention relates to an angular velocity sensor, an electronic apparatus and a mobile object which include the angular velocity sensor.
2. Related Art
In the related art, a gyroscope (hereinafter, referred to as an angular velocity sensor) with a configuration in which a plurality of drive masses (hereinafter, referred to as mass units) disposed on a substrate as an angular velocity sensor corresponding to angular velocities of three detection axis rotations are coupled to each other by elastic coupling elements (hereinafter, referred to as coupling units), at least one mass unit is subjected to drive movement (hereinafter, referred to as drive vibration) by a drive unit, and thereby the drive vibration is transferred to another mass unit through the coupling unit, further, in a state in which a plurality of mass units is subjected to the drive vibration, angular velocity which is applied thereto is detected using detection vibration of detection units which are provided in a plurality of mass units, is known (for example, refer to European Patent Application Publication No. 2339293).
In an embodiment, the angular velocity sensor has a configuration in which two mass units (hereinafter, referred to as first mass pair) are subjected to drive vibration directly by a drive unit, thereby the drive vibration is transferred with a given rate to the other two mass units (hereinafter, referred to as second mass pair) through a coupling unit, and a total of four mass units is subjected to the drive vibration.
However, there is a possibility that, in the angular velocity sensor, the given rate may not be approximately 1:1 due to consumption of drive vibration energy or the like caused by, for example, a coupling unit having elasticity.
For this reason, there is a possibility that, in the angular velocity sensor, an amplitude of the drive vibration of the second mass pair to which the drive vibration is transferred from the first mass pair through the coupling unit may be smaller than an amplitude of the first mass pair which is subjected to drive vibration directly by a drive unit.
As a result, there is a possibility that, in the angular velocity sensor, an amplitude of detection vibration of a detection unit of the second mass pair at the time of applying angular velocity may be smaller than an amplitude of a detection unit of the first mass pair, and thus there may be a difference between detection sensitivities of detection axis rotation of each of three detection axis rotation angular velocities which are detected by detection units of the four mass units.
Due to this, there is a possibility that detection characteristics of the angular velocity sensor may be degraded.